Peugeot 307 Engine Cooling Fan Doesn't Work

[Cantthinkof12use]

We have a 57 plate Peugeot 307 and last summer it developed a fault where the engine cooling fan doesn't kick in. Also the air con doesn't work although we are not concerned with this but wondered if it's linked. We took it to a couple of local garages who couldn't find the fault so we left it over the winter, but with summer coming up we really ought to get it sorted. Have just rang Peugeot and they charge £98.40 to run a diagnostic for up to an hour that's without fixing any fault they find. Does anyone have any experience of this fault and what was / could the problem be? TIA

[Davethedog]

http://www.autoinsider.co.uk/problems/show.php?problem=5685

Does this cover it?

[bhg481]

No experience with Peugeot but there's usually a sensor screwed into the engine block which earths the cooling fan circuit when the engine temperature gets high enough for the fan to be needed. The sensor on my Vauxhall failed, so no cooling just when it mattered. Usually simple to replace but you might need a manual to determine its location - probably a single wire running to it, the colour will be in the manual. If you find the sensor you can test it by removing the wire from it and putting the wire to earth eg, engine block, the fan should start.

[Cantthinkof12use]

Thanks both. I'll pass your comments on to my hubby, see if he can fathom it out!

[Graham-W]

The engine temperature sensor is usually near the thermostat on the engine side of it.

[bhg481]

Graham - I think the one you're talking about is the one for the gauge on the dashboard. The one for the fan operation on my Vauxhall was at the bottom of the radiator, the idea being that if the water reaching the bottom of the radiator was too hot, not enough cooling had taken place in the radiator, so the fan was necessary for additional cooling.

[Graham-W]

I stand corrected bhg. It will, indeed, be in the radiator and not the thermostat.

[tonyav]

This is what the Haynes book say's.
There is only one coolant temperature sensor on most models, which is fitted to the coolant outlet housing on the left hand end of the cylinder head. The coolant temperature gauge and the cooling fan are all operated by the engine management ECU using the signal supplied by the sensor. However on the 1.4 and 1.6 litre models two sensors are fitted. The one fitted to the outlet housing is for the temperature gauge , and the one screwed into the left hand end of the cylinder head is for the engine management ECU.

So I would guess that the sensor that tells the ECU what temperature the coolant is as failed, if not then it is most likely a ECU fault, fingers crossed for you that it is just a dodgy sensor.